1. Technical Field
Embodiments of the present invention relate to a toner collection unit that stores toner such as waste toner collected from units and components provided in an image forming apparatus, and an image forming apparatus including the toner collection unit therein.
2. Related Art
In electrophotographic image forming apparatuses, toner is transferred from a photoconductor onto a transfer belt and from the transfer belt onto a recording medium. In performing these toner transfer operations, it is difficult to achieve a perfect or 100% transfer rate, and therefore residual toner remains on the photoconductor and the transfer belt after the toner transfer operations. The residual toner is collected by a cleaner having a suitable configuration for operations in each electrophotographic image forming apparatus and stored as waste toner in a toner collection unit provided in the image forming apparatus. As the amount of waste toner stored in the toner collection unit approaches a full state, a message is issued to report the status of the toner collection unit. In response to the report, a user or a service engineer replaces the toner collection unit to a new unit or disposes the toner collection unit.
As an example of detection that an amount of waste toner of a toner collection unit approaches the toner full state, Japanese Patent Application Publication No. JP 2009-199005-A discloses a configuration in which a flexible seal is provided to a waste toner collection unit in a downwardly warped manner, as illustrated in FIGS. 9 and 10 thereof. When the waste toner collection unit is filled with waste toner, the flexible seal is warped upwardly. This deformation of the flexible seal pushes up a moving member, so that a photointerrupter detects movement of the moving member.
However, even though the flexible seal is deformed due to accumulation of waste toner in the waste toner collection unit, the shape of the flexible seal does not change uniformly over the whole flexible seal. Actually, it is likely that the change of shape of the flexible seal occurs irregularly and unevenly and the flexible seal has locally deformed areas on a surface thereof. Therefore, the locally deformed areas of the flexible seal may be caught at an edge of the moving member or be pried at a support portion of the moving member. Such unevenly changed flexible seal can apply a load to the moving member when the moving member moves. Consequently, the photointerrupter causes a delay in detecting the full state in the waste toner collection unit, which is likely to cause leakage of waste toner.
As disclosed in JP 2009-199005-A, the moving member is disposed in a recessed space of the flexible seal in an initial condition that is a condition before waste toner is collected to the waste toner collection unit. FIG. 1 is an example drawing that illustrates a position of a moving member in the initial condition. As illustrated in FIG. 1, when a flexible seal 330 is warped or bulged out, the flexible seal 330 easily comes into a gap between the moving member 300 and an edge of an opening 320 of a waste toner collection unit 310. Consequently, it is likely that the flexible member 330 twines around the moving member 300. In this case, a load is applied on the moving member 300 when the moving member 300 moves. Therefore, the above-described inconveniences become obvious.